Vitrines are containers made of glass or other hard, essentially transparent material that are used to display items in museums, shops, or homes. The quality required for a vitrine is dependent upon the purpose for which it will be used. Typically, museums and some shops, which display rare, intricate, and valuable items, seek vitrines that provide a secure yet uninterrupted and virtually invisible barrier between the displayed item and the observer. The transparent material used to provide such a barrier may be, for example, glass or acrylic. The acrylic material may have an anti-reflective material coating on its surface to minimize reflective visual distractions caused by extraneous light sources.
Most vitrines are made up of multiple flat panels that are joined in some manner to provide structural integrity. To minimize visual disturbance, vitrines may be designed so that the transparent panels are joined without opaque framework. In such designs, an adhesive may be used to join the panels. Where such panels are joined by an adhesive, a seam is created. The viewing experience through the panels of such a vitrine is substantially enhanced if the seam can be made to be virtually invisible. It is an object of the present invention to minimize and virtually eliminate the visual disturbance created by such a seam.
Current seaming techniques often result in seams with bubbles, which create optical distortion, or cause the appearance of the vitrine to deteriorate over time. If a flaw does appear, the panels normally must be discarded. Multiple failures are common, such that achieving a clear seam without flaws is typically very expensive.
One device that utilizes an adhesive for joining glass panels was presented in U.S. Pat. No. 3,651,975, for purposes of an aquarium. In this device, the panels are interconnected with fillets of adhesive that provide, in part, the ability to fold the panels upon themselves for transportation. The method disclosed for creating this form of glass enclosure consists of joining together panels, which each have 90 degree edges, with a large wedge of adhesive forced into the joint by a device such as a caulking gun. The large wedge of adhesive, the method of application, and the required adhesive smoothing and excess adhesive removal techniques presented, are likely to result in a translucent type joint with bubbles and other flaws, and are unlikely to result in an essentially fully transparent seam necessary for an uninterrupted viewing experience from varying angles that should be provided by a high quality vitrine.
Another such device was presented in U.S. Pat. No. 3,927,643, which also relies in part upon the use of an adhesive to join panels. This device uses mitered joints rather than 90 degree joints, so that a smaller amount of adhesive is necessary. The method disclosed for joining adjacent panels, however, relies upon simply laying a uniform strip of adhesive between the mitered joints before joining them together, apparently by pressure. Such a technique will frequently result in bubbles and other visually disturbing flaws in the seam.
Abrasion-resistant acrylic panels, typical of high quality vitrines, have a hard coating that pose additional problems. Abrasion-resistant panel material generally will not react with the adhesive. Thus, in order to apply an adhesive to a surface of an abrasion-resistant coated panel, the coating must be mechanically removed in the bond area of panel edges to be joined.